In various types of construction machinery, tools are provided which engage material to be processed, especially highly abrasive materials such as rock, stone and gravel, in a certain direction or orientation, the abrasive action of such engagement causing significant wear and detriment to the tool. A case in point is rock-breaking machinery such as hammer mills and crushers, in which the tool elements are involved in such abrasive action and are subject to such wear.
In the past, efforts have been made to fabricate these parts of such machines from extremely expensive wear-resistant steels, commonly such steels as are designated high-alloy steels and especially steel alloys rich in manganese.
These materials, however, cannot readily be forged, and therefore the machine parts must be cast in the desired configuration or in a configuration close to the desired configuration and, of course, possess a lattice, crystalline or like internal structure characteristic of such casting.
Such materials can be machined only with difficulty, tend to be somewhat brittle and when subjected to abrasive wear cannot readily be dressed.
The tool elements frequently must be machined whether for sharpening or for shaping them to a given configuration or to compensate for various factors which may be present in use of the machine. As a result, the fact that the tools are cast in forms which make machining difficult and in structures which scarcely can be machined effectively is a significant detriment. Mention should also be made of the fact that when crushing jaws or the like are fabricated from such earlier materials for use in rock-breaking machinery, they tend to have insufficient abrasion resistance as well.